docs: def result_report_class_wise(self):
          """Report class-wise results
  
          Returns
          -------
          str
              result report in string format
  
          """
  
          results = self.results_class_wise_metrics()
  
          accuracy_present = True
          for event_label in self.event_label_list:
              if 'accuracy' not in results[event_label]['accuracy']:
                  accuracy_present = False
  
          output = self.ui.section_header('Class-wise metrics', indent=2) + '\n'
  
          headers = ['Event label', 'Nref', 'Nsys', 'F', 'Pre', 'Rec', 'ER', 'Del', 'Ins']
          sep = ['-', '-', '-', '-', '-', '-', '-', '-', '-']
          widths = [15, 8, 8, 9, 9, 9, 9, 9, 9]
          separators = [True, False, True, False, False, True, False, False, True]
          if accuracy_present:
              headers += ['Sens', 'Spec', 'Bacc', 'Acc']
              sep += ['-', '-', '-', '-']
              widths += [9, 9, 9, 9]
              separators += [False, False, False, False]
  
          output += self.ui.row(*headers, widths=widths, indent=4, separators=separators) + '\n'
          output += self.ui.row(*sep) + '\n'
          for event_label in self.event_label_list:
              data = [
                  event_label,
                  results[event_label]['count']['Nref'],
                  results[event_label]['count']['Nsys'],
                  results[event_label]['f_measure']['f_measure'] * 100,
                  results[event_label]['f_measure']['precision'] * 100,
                  results[event_label]['f_measure']['recall'] * 100,
                  results[event_label]['error_rate']['error_rate'],
                  results[event_label]['error_rate']['deletion_rate'],
                  results[event_label]['error_rate']['insertion_rate']
              ]
  
              types = [
                  'str15',
                  'int',
                  'int',
                  'float1_percentage',
                  'float1_percentage',
                  'float1_percentage',
                  'float2',
                  'float2',
                  'float2',
              ]
  
              if accuracy_present:
                  data += [
                      results[event_label]['accuracy']['sensitivity'] * 100,
                      results[event_label]['accuracy']['specificity'] * 100,
                      results[event_label]['accuracy']['balanced_accuracy'] * 100,
                      results[event_label]['accuracy']['accuracy'] * 100
                  ]
  
                  types += [
                      'float1_percentage',
                      'float1_percentage',
                      'float1_percentage',
                      'float1_percentage',
                  ]
  
              output += self.ui.row(*data, types=types) + '\n'
  
          return output